Syrian activists dispute precisely how many jihadis were broken out of prison by the assault on Ghuwayran last week, but it's likely that hundreds were freed.
Syrian Kurdish officials stressed that their spy and their months of work with the CIA were crucial to the U.S. raid that took out the ISIS leader.
Beyond the rising death toll, the assault has sparked a mass exodus of civilians, with at least 70,000 people having fled border towns.
The two notorious ISIS executioners were moved to U.S. custody amid fears of mass ISIS prison breaks during Turkey's invasion of Syria.
Least of all Trump.
“ISIS has been waiting for this,” said one anti-ISIS campaigner who fought for Kurdish forces. “It’s going to be a nightmare.”
The world wants to wash its hands of the people who have escaped the Islamic State.
“Allies will suffer, Assad and Iran and Russia will gain.”
The Islamic State has ignored an offer for its fighters to withdraw safely from the Syrian city of Manbij, and clashes with US-backed forces continued after the offer expired.
US-backed forces fighting Islamic State near the Syrian-Turkish border said on Thursday they had reached the militants' last main route in and out of their stronghold in the area, the city of Manbij.